Various forms of flow device are used for carrying a flow of blood in an apparatus for measuring the blood hemorrhaging time. Thus, the apparatus for measuring hemorrhaging time in vitro, as disclosed in German laid-open application (DE-OS) No. 32 47 810, uses a through-flow device having a separating wall in the form of a porous member with an aperture therein. The porous member is supported on a support structure which is not permeable to air, and is of such a design configuration that blood passes only through the aperture therein, and cannot flow round the sides of the porous member. That provides an apparatus, and therewith a method, for measuring hemorrhaging time in vitro, in which it is possible to simulate the hemorrhaging processes under in-vivo conditions.
In another form of hemorrhaging time measuring method, as disclosed in German laid-open application (DE-OS) No. 35 41 057, the blood to be tested is sucked into a capillary tube under a given reference suction force which is produced with a control feedback, wherein the amount of blood flowing in the capillary is ascertained as a measurement in respect of aggregation or coagulation of the thrombocytes. That arrangement also makes it possible accurately to simulate hemorrhaging processes under in-vivo conditions.